The present invention is directed to electrical connectors and more particularly to keying systems for electrical connectors.
When mating electrical connections various methods are used to assure that connectors are mated correctly. This is particularly important when, for example, a series of electrical cables are to be connected to the same device. If the cables have different numbers of conductors or different sizes of conductors to be terminated to a connector, the connectors generally will be different sizes and, therefore, easy to match to the mating connector of the device. In addition to size differences, the connectors may also be polarized to assure correct orientation of the connectors prior to mating. The housing may have an asymmetric shape, such as, for example, a D-shape, or an interlocking rib and notch along a wall of the housing or other orientating features, as known in the art.
If, however, the cables are substantially identical and an array of same size and shape connectors are to be terminated to the cables, a keying system is also used to assure that the correct pairs of connectors are mated. Various systems have been used, such as plugs that are inserted into selected terminal passageways or keying features on flanges that extend outwardly from the sides of the housings.
To be cost effective it is desirable that the keying system be one that is programmable, that is, the key can be changed from one position to another in the same connector housing, thus eliminating the need to stock many differently keyed housings.
It is further desirable that the keying system be one that permits connectors to be spaced closely together on a back plane or the like to help minimize the size of the device being manufactured.
The present invention is directed to an electrical connector having a keying system that overcomes problems associated with the prior art. The connector includes a housing with a mating face and an assembly face and an array of terminal receiving passageways extending therebetween, a plurality of terminals, and a programmable keying member. Each terminal is disposed in a respective terminal receiving passageway. The housing includes a key receiving opening extending into the mating face disposed among the array of the terminal receiving passageways and configured to receive the keying member in any of a plurality of orientations.
The invention is further directed to a connector wherein the key receiving opening extends to the assembly face and the keying member further includes at least one other terminal disposed in a terminal receiving passageway of the keying member.
For purposes of illustrating the invention, the connector is shown as a shielded circular power connector having ground, neutral and power terminals and a keying member that includes signal terminals. The signal terminals may be used, for example, to transmit control signals through the connector to an apparatus. It is to be understood that the invention is not limited to circular connectors nor to shielded connectors nor to power connectors. Furthermore the keying member may include no additional terminals, terminals that are similar to the other terminals in the connector or terminals that are dissimilar to the other terminals.
The present invention provides a keying system that is contained within the outer profile of the connector housing and does not extend outwardly from the ends or exterior walls of the connector thereby enabling the connectors to be spaced closely together on a back plane or the like.
An embodiment of the invention will now be described by way of example with reference to the accompanying drawings.